Psychosocial factors associated with non-smoking adolescents' intentions to smoke

Smoking is the most preventable cause of death in the United States. Most adult smokers began smoking during adolescence, making youth tobacco prevention an especially important public health goal. Guided by an extension of the theory of planned behavior (TPB), this study examined the role of psychosocial factors in accounting for adolescents' smoking intentions. Participants from three high schools (n = 785) were surveyed to assess smoking-related characteristics and behaviors as part of a statewide evaluation of tobacco prevention programming. Attitudes, subjective norms (and other normative factors) and perceived behavioral control were all associated with non-smokers' intentions to smoke. Having more favorable attitudes toward remaining tobacco free and perceiving that friends would not be supportive of smoking were both associated with decreased likelihood of intending to smoke. Normative influence and peer use were significant factors, such that having more friends who smoke was associated with increased odds of intent to smoke. Lastly, perceived difficulty to quit was related to smoking intentions, with higher confidence to quit significantly associated with intentions to smoke. Findings are consistent with the TPB--attitudes, normative factors and perceived behavioral control each helped account for non-smoking adolescents' intentions to smoke. Implications for theory and intervention building are discussed.     

Characterization of breakthrough hemolysis events observed in the phase III randomized studies of ravulizumab versus eculizumab in adults with paroxysmal nocturnal hemoglobinuria

Eculizumab is first-line treatment for paroxysmal nocturnal hemoglobinuria (PNH); however, approximately 11-27% of patients may experience breakthrough hemolysis (BTH) on approved doses of eculizumab. Ravulizumab, a new long-acting C5 inhibitor with a four times longer mean half-life than eculizumab, provides immediate, complete, and sustained C5 inhibition over 8-week dosing intervals. In two phase III studies, ravulizumab was non-inferior to eculizumab (Pinf ≤0.0004) for the BTH endpoint; fewer patients experienced BTH with ravulizumab versus eculizumab in both studies (301 [complement inhibitor−naïve patients], 4.0% vs. 10.7%; 302 [patients stabilized on eculizumab at baseline], 0% vs. 5.1%). In the current analysis, patientlevel data were evaluated to assess causes and clinical parameters associated with incidents of BTH reported during the 26-week treatment periods in the ravulizumab phase III PNH studies. Of the five BTH events occurring in ravulizumab-treated patients across the studies, none were temporally associated with suboptimal C5 inhibition (free C5 ≥0.5 mg/mL); four (80%) were temporally associated with complement-amplifying conditions (CAC). Of the 22 events occurring in eculizumab-treated patients, 11 were temporally associated with suboptimal C5 inhibition, including three events also associated with concomitant infection. Six events were associated with CAC only. Five events were unrelated to free C5 elevation or reported CAC. These results suggest that the immediate, complete, and sustained C5 inhibition achieved through weight-based dosing of ravulizumab reduces the risk of BTH by eliminating BTH associated with suboptimal C5 inhibition in patients with PNH. (Registered at clinicaltrials.gov identifiers: Study 301, {"type":"clinical-trial","attrs":{"text":"NCT02946463","term_id":"NCT02946463"}}NCT02946463; Study 302, {"type":"clinical-trial","attrs":{"text":"NCT03056040","term_id":"NCT03056040"}}NCT03056040.)     

Vitamin D, osteocalcin, and risk for adiposity as comorbidities in middle school children

Nonclassic actions of vitamin D include potential regulation of immune function and glucose homeostasis. The bone-metabolism loop has recently been expanded to include osteocalcin, which appears to play a more direct role in pancreatic beta cell function and energy metabolism. We hypothesized that both vitamin D and osteocalcin would correlate negatively with indices of adiposity-related comorbidity risk in periadolescents, varying by ethnic group. We analyzed anthropometric, metabolic, and inflammatory markers from a multiethnic population of 106 school children 11 to 14 years of age studied as part of the Reduce Obesity and Diabetes (ROAD) consortium. As expected, 25-hydroxyvitamin D (25-OH vitamin D) was inversely correlated with intact parathyroid hormone (iPTH); total osteocalcin (OCN) and uncarboxylated osteocalcin (uOCN) were directly correlated with each other. OCN and uOCN concentrations correlated inversely with age. Vitamin D deficiency was most prevalent among East Asians (EA) and African Americans (AA). The highest lipid risk scores and homeostatic model for assessment of insulin resistance (HOMA-IR) values were seen in the South Asian (SA) group. Overall, adiposity measures were inversely correlated with OCN and iPTH, whereas such relationships were not observed for vitamin D. Acute insulin response to glucose challenge correlated negatively with uOCN in all subjects; however, lipid risk score correlated negatively with uOCN only in whites. The relationships between markers of calcium metabolism and body composition, glucose homeostasis, lipids, and inflammation all showed racial and ethnic differences. No consistent relationship was found between vitamin D and adiposity or vitamin D and glucose metabolism; instead vitamin D levels varied by race and ethnicity in this school-based group. These findings are consistent with the hypothesis that markers of calcium and bone metabolism may reflect risk for adiposity-related comorbidities in children.     

High-Risk Behaviors and Hospitalizations Among Gamma Hydroxybutyrate (GHB) Users

Introduction: Little is known about behaviors linked to gamma hydroxybutyrate (GHB) morbidity. Methods: We surveyed 131 GHB users, using logistic regression to test the associations between the high risk behaviors and hospital treatment for GHB (26 [20%] of subjects). Results: Increased risk of GHB hospital treatment was associated with: co-ingestion of ethanol (OR 5.2; 95% CI 1.7–16), driving under the influence of GHB (OR 3.2; 95%, CI 1.3–7.8),use of GHB to treat withdrawal symptoms (OR 2.9; 95% CI 1.1–7.9), and co-ingestion of ketamine (OR 2.7; 95% CI 1.1–6.7). Conclusion: Targeted prevention activities could focus on selected high-risk behaviors.     

CIRCUMCISION: Refining a Traditional Surgical Technique

Circumcision is a practice that dates back to the Stone Age, when flint knives were used to perform this delicate task. Since that time, different implements and techniques for their use have been employed. In 1935, an instrument that reduced the incidence of hemorrhage and infection, which continued to complicate circumcisions, was first described in the medical literature of this country; for nearly 60 years, the Gomco clamp has met and exceeded expectations despite the emergence of other clamps and devices. This article addresses refinements that have evolved in the Gomco clamp technique. These refinements combine the highest degree of safety with the least trauma to the newborn. Step-by-step detailing of this surgical skill and implications for practitioners are explored in depth.     

Lack of effect of hyperprolactinemia on serotonin turnover in ovariectomized and ovariectomized estrogen-treated rats

Hyperprolactinemia suppresses luteinizing hormone (LH) and prolactin (PRL) secretion under a variety of experimental conditions. The secretion of both of these hormones is regulated at the hypothalamic level by several neurotransmitters, including serotonin (5-HT). Therefore, we examined the effect of hyperprolactinemia on 5-HT neuronal activity in key hypothalamic areas that are rich in 5-HT terminals and which are known to regulate the release of LH and PRL. Young cycling virgin rats were ovariectomized (day 0). From days 11-16, animals were injected with ovine prolactin (oPRL, 4 mg/kg, s.c.) or vehicle every 8 h. On day 14, one-half of the oPRL- and vehicle-treated rats were implanted with 20-mm long Silastic capsules containing estradiol (180 micrograms/ml). On day 16, animals were killed at 08.00, 12.00 or 18.00 h or treated with pargyline (75 mg/kg) and killed 10 min later. Trunk blood was collected and serum was radioimmunoassayed for LH and endogenous rat PRL (rPRL). Brains were removed, frozen, sectioned and the medial preoptic, suprachiasmatic, and arcuate nuclei, median eminence and globus pallidus were microdissected. Serotonin was measured using high pressure liquid chromatographic methodology. We were unable to detect any feedback effect of hyperprolactinemia on 5-HT turnover in any brain area of ovariectomized or ovariectomized estradiol-treated rats at any time of day that we examined. Several potential reasons for the absence of an effect of hyperprolactinemia on serotonergic function are discussed.     

Ontogeny of cephalic insulin release by the rat

Developmental aspects of cephalic insulin release in rats were evaluated by examining insulin secretion in response to the sweet taste of saccharin at different ages. A cephalic insulin response was present at the time of normal weaning (21–22 days) and by 34 days of age its magnitude was indistinguishable from that of adults. The early appearance of cephalic insulin release prompted a second study examining whether this response is present at birth; i.e., prior to any suckling experience. In newborn rat pups, no increase in plasma insulin was seen as a result of introduction of saccharin into the oral cavity. It was concluded that maturational and/or learning changes responsible for cephalic insulin release occur during the suckling period. The discussion concerned whether these changes involve maturation of the afferent loop, the efferent loop and/or learning as a consequence of the suckling experience.